The present invention relates to a vent line in the cooling circuit of an internal combustion engine, the vent line connecting a radiator to a top section of an expansion tank located at a higher level with regard to the top of the radiator. An angled pipe element of the vent line dips into the expansion tank at a top section, the angled pipe element having an opening in the vicinity of the tank bottom.
U.S. Pat. No. 4,677,943 discloses a vent line of the above type. In this arrangement, it is disadvantageous that the air volume into the expansion tank by the expansion of the cooling water is held back in the vent line by the geodetic back pressure of the cooling water located in the expansion tank. This air volume remaining in the vent line is drawn in by the water pump when the engine is restarted. Damage to the pump consequently occurs, the entire cooling circuit being disturbed.
An object of the present invention is to provide a bent line to be installed between an expansion tank and a radiator, in which vent line the trapping of an air volume is avoided.
This and other objects are achieved by the present invention which provides a venting arrangement in a cooling circuit of an internal combustion engine, and has an expansion tank and a vent line that couples the top section of the expansion tank with a radiator of the cooling circuit. The vent line is at least as high as a top of the radiator, and has an angled pipe element that dips into the expansion tank at the top section. The angled pipe element has an opening in the vicinity of a bottom of the expansion tank. The vent line also has a pipe section which lies in the expansion tank and is coupled to the angled pipe element, and a vent valve that is arranged at a highest point of the vent line.
In effect, a vent valve is installed at the highest point of the vent line. Via this vent valve, the air displaced during travelling operation from the radiator and during the filling of the expansion tank and the radiator can escape. The pipe element of the vent line, (the pipe element containing the vent valve), is arranged in an advantageous manner inside the expansion tank so that the cooling water expanding during the running of the engine and discharging via the vent valve remains in the expansion tank.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.